Is your DH aware that SD says these things? If not, it's time to have a heart-to -heart with him and tell him.

"DH, SD has made it clear that it makes her uncomfortable to have a close relationship with me because of loyalty to her mom. She's young and worried, and I won't add to that. I will let her dictate her relationship with me, even if that means she doesn't have one. If that is unacceptable to you, then you can talk to her about her feelings. If she shows interest in building a relationship, I will foster it. However, I will not force her to have a relationship with me."

Make it very clear what you will and won't do. Make it clear that if he doesn't approve of her behavior that it is HIS job to correct it, not yours. If he brings up how it's so easy with your sons, remind him that you parent them differently than BM does SD and that they are different children. No need to say anything disrespectful; just keep reiterating that everyone handles the same situation differently, and that your way of handling this one is to let SD come to you. There is absolutely nothing wrong with that approach.

Your DH is comparing apples to gorillas and you need to point this out. That your kids come running to him and enjoy spending time with him, because YOU encourage the relationship. SD is standoffish towards you because her mother is a nutcase who is hampering the relationship. And does your DH realize that his guilting you about it and "forcing" a relationship doesn't help matters?

Have you tried doing parallel activities? Have a craft or art project set up to do while she is there...just start doing it...if she is interested...have her join you at the table with her own supplies. Don't make a big deal of it. If she mentions BM just redirect conversation.
Same with a game, sport activity or family activity.
She is only four...take the lead and she likely will follow. Make it fun and interesting but keep it genuine. Keep it within your budget or free also. Collecting fall leaves and acorns and fossil rocks in the park can be fun for kids. It does not have to be grand gestures.
Mud pies can be fun! Blowing bubbles!
Paint your own nails...likely she will want hers done too. You can always remove the polish before she goes home if it will be a problem with BM. Or do face painting for the day...just use proper paint for skin.

It takes time...especially as she does not live full time with you. Tell DH to stop pressuring to make it happen instantly.

Sounds like the little girl is in a loyalty bind. The only person who can release her from that bind is her mother.

Your DH should say something to BM, not to you. He can't hold you accountable for things his ex is doing to his child.

If I were you, I would just tell the little girl that you don't want to do anything that will make her feel bad, or scared and if she doesn't want to do something because she's afraid of what her mother will think, then she doesn't have to.

I think if you are kind to her and don't force her into anything, she may eventually see you as non-threatening. The caveat there is that she's young and if her mother has already started saying negative things about you, it may take the girl into adulthood to figure out that her mom was lying to her.

But, your DH needs to understand this dynamic, so he's not holding it against you. There's no "correct" relationship to have with a stepchild. Ideally, you'd have whatever relationship that allowed both you and your SD to feel comfortable and respected, even if that means the two of you aren't super close.

Ye Olde "SM should try harder" crap
So, yeah, just pick a random kid down the street, whose parents hate you and try to win over said kid by "being nice." Yeah that'll work. :sick: :sick:

Your DH is in the "one big happy family" model and "turn the other cheek/benefit of the doubt\take the high road with BM" model. Oh and "SD is just a kid--you're the adult here and you should try harder" model (TM)

All of these old chestnuts are complete and utter failures. Disengage and just maybe do a few fun things that SD can join in on.

You do know that the BM is interrogating SD when she comes back--"did you have a good time with SM and DH? You DID? Well that'll be punishment for YOU, young lady."

Stop trying, you are putting SD in a tough spot....she's 4 years old, normally they like all people, BM is poisoning her mind... simply stop trying, tell DH to stop pressuring her as well...

This is what you can do, never ask her to help you or do something with you, simply get coloring books, sit and color, do some art thing age appropriate for her... you will see she will simply come closer to you and ask if she can do it as well, then hand her her stuff and say sure, still not speaking to her... let her be the one engaging with you, answer her questions etc... after a month or so, she will open up more and you can simply tell her it's your little secret...

I think there's many ways of bonding without her thinking of BM, she's still young

I think when she says 'My mommy said no, mommy doesn't like you etc etc' then I would just reply that ok but I don't want to hear about that. You can decide if you want to like me and i'm just going to be doing 'insert parallel activity suggested by Lostinspace' and you can join me if you want.

End of. She can process that. You will probably have to say this a few times but she will eventually get the message. If she sees a reaction from you about the 'my mommy says..' stuff then she will keep doing it because i'm sure her BM is filling her with these ideas and pumping her for information about your reaction when she gets back.

Is there a reason why nobody advocates having her DH try to explain to SD that the BM or "mommy" is lying/manipulating/brainwashing/being a crappy parent? That the BM clearly doesn't care about SD's best interests if she goes around trying to destroy her relationships with family members? That SD is not to listen to anything BM says about SM because the BM doesn't know SM and anything she says is a lie?

It looks like if BM is working on turning the child against the OP, possibly her DH as well. Anybody who knows anything about parental alienation knows it only gets worse, and knows that taking the high road usually results in completely losing the child to other parents manipulations. The child doesn't realize it on their own, often not even when they're adults.

If the OP and her DH continue to allow this, by the OP disengaging or her husband not supporting her, it pretty much guarantees her 14 years of having a brainwashed child that strongly dislikes her for no good reason living with her some of the time and as part of her family. If the BM includes DH in her smear campaign, she will have a brainwashed self hating angry child who hates her in her house for the next 14 years. If she disengages now, and allows the BM to continue doing what she is doing, its 14 years of discomfort and misery. If they refuse to speak badly about the BM, and choose to remedy this problem by tricking the child into spending time with SM it will only go so far, and will likely also result in 14 years of discomfort and misery.

Can anyone explain why they don't recommend fighting fire with fire here?

I agree that fighting fire with fire is generally reputed not to be in the child's best interest. However--

It is fairly certain that the BM is manipulating and brainwashing SD with the goal of turning her against SM and probably DH as well. Assuming that we can get DH to be supportive, and assuming that OP wishes to stay in her relationship, there are several courses of action being recommended to her, that would be considered morally good, right, and in the best interest of the child.

Unfortunately, all recommended courses of action are likely to have the same outcome. SD will gradually become more and more spiteful towards the OP, probably eventually refusing to be around her completely. The false claims of being abused by SM are likely to escalate, and its likely CPS will come and investigate, repeatedly. Its also likely they won't find anything, but you can expect years of anxiety and obsessive housecleaning and documenting EVERYTHING you do just incase someone claims you were abusing them so you can defend yourself. Even if nothing is ever filed in court and nothing ever comes of up, be prepared to spend the next 15 years on your toes waiting for the other shoe to drop.
SD will likely also become spiteful towards DH, either because BM is telling her to be, or because she is angry that DH is forcing her to be around the evil SM. This hatred of her father will eventually transform into hatred of herself, because she recognizes that she is half DH. Over time this will eventually result in SD developing a myriad of disfunctional behavioral issues from lying to drug use to theft and promiscuity. If DH insists on continuing to use his time with SD, SD will rebel like crazy and make any time spent with her absolutely and completely miserable. She will basically do whatever she can think of to get SM and DH out of her life completely until DH gives up on her. She will have severe difficulty forming relationships with other people for the rest of her life, and will likely grow up to be a single parent herself, while perpetrating BM's abuse upon her own children.

In the eyes of a small child, mother is God. SD will follow god's divine instructions, no matter how much you try to trick her into hanging out with you, and no matter how much you try to explain to her that lying is bad and that saying bad things about SM is not nice. Because god has already commanded her to do these things. It doesn't matter how nice the OP is to SD because it doesn't matter how nice the devil (or things believed to be the devil) are to a religious zealot. The only thing that matters is the word of god.
As SD gets older, she will realize that her mother is not god, but by then all of the things that BM said to SD will have been internalized, and will be a part of the fabric of her being. So it is highly unlikely that she will ever realize that BM was the problem in all of this and that BM is the reason her life is such a mess. And even if she does realize it, she will not know how to stop her life from being a mess. Children continue to live the mistakes of their parents throughout their entire lives.

Do you really believe that this outcome is in the SD's best interests?

The only way to save a religious zealot is to slowly and repetitively undermine and destroy their entire religion, piece by piece, this would be reverse brainwashing. The only way SD can possibly be saved, is to "reverse brainwash" a child's innate biological bonding to their primary caregiver, in this case, the BM. You need to teach her now, at age 4, much to early, that god (BM) is not god. This is a realization most people don't have until their teens or twenties. Some never have it.

I agree that this will probably be traumatic for SD, but its not nearly as traumatic as the outcomes detailed above. The only way to save SD is to strip this emotionally abusive POS of her power, and reduce her in SD's mind and heart from god to simply the woman who gave birth to her. A cruel, abusive, and manipulative woman that could easily have been replaced by any other fertile female willing to take care of her or even SM herself.
You will need to teach her that her mother is of no value to her. If SD knows that BM lies, and SD knows that what BM says is not important and not to listen to her nonsense, than BM's manipulations will cease to be effective. You also need to teach SD that her BM is not any reflection upon her. She needs to understand that she is not her mother, because you don't want her to believe that she is bad just because mommy is bad. (This aspect is why PAS is so damaging, a child who learns to hate a parent does not know that they are not their parent yet, so they also learn to hate themselves.) You need to first teach SD that she is not the BM and that she is not anything like the BM, and then concurrently teach her that the BM is not to be respected or believed.

These are your choices. Do nothing, and take a 90% chance of ruining your life (should you choose to stay,) your DH's life and SD's life, or fight fire with fire, which may not be in the best interests of the child, but may save all three of you at the expense of the true abuser, the BM.